This invention relates to a V-type, fuel injection, two cycle engine and more particularly to an improved layout of the induction and fuel injection system for such an engine, particularly as applied to an outboard motor.
Because of the numerous advantages of two cycle, internal combustion engines, they are frequently used as the power plant in marine propulsion units such as outboard motors. However, as the requirement for greater power outputs exist, certain problems result in connection with the layout of the various components of two cycle engines. Particularly, because of the necessity for a very compact engine relationship, there is some difficulty in laying out certain of the components for an engine having multiple cylinders, particularly when applied in an outboard motor application. For example, it is known that an engine of a given displacement can be more compact if the cylinders are arranged in banks disposed at an angle to each other. Such engines are normally called "V-type" engines.
However, when the engine is also of the two cycle, crankcase compression type, it has been the practice to design the induction system so that it supplies a charge directly to the crankcase chambers of the engine from the crankcase side of the engine. This means, of course, that the engine tends to become rather bulky with the cylinder banks extending from one side of the crankcase and the induction system extending from the other side of the crankcase.
It is, therefore, a principal object to this invention to provide an improved induction system for a V-type, crankcase compression, internal combustion engine.
It is a further object to this invention to provide a compact engine and induction system of the two cycle, V-type crankcase compression type.
In addition to the problems of the air induction for the crankcase chambers of the engine, there is also the consideration of providing fuel for the charge forming system of the engine. If carburetors are employed, they generally discharge into an intake manifold which, in turn, supplies the charge to the crankcase chambers. However if the induction system is on the opposite side of the crankcase from the cylinder blocks and such a carburetor intake manifold system is employed, the engine becomes even more bulky.
It is, therefore, a still further object to this invention to provide an improved fuel injection and induction system for a two cycle, crankcase compression, internal combustion engine.
It is a further object to this invention to provide an improved and compact fuel injected, crankcase compression, V-type, two cycle internal combustion engine.
When fuel injectors are employed and a manifold type of injection system is incorporated, then additional problems result in the design of the induction system. That is, the fuel injector should be disposed in such an area that they spray a fairly uniform fuel spray across the induction passage into which they inject. Also, it is normally the practice to employ a check valve arrangement in the induction system of the two cycle, crankcase compression engine so as to preclude reverse flow through the induction system when the charge is being compressed in the crankcase chambers. It is important to insure an appropriate interrelationship between the location of the fuel injectors and the check valves so as to insure uniform fuel distribution.
It is, therefore, a still further object to this invention to provide an improved fuel injected, crankcase compression, V-type, two cycle internal combustion engine including check valves in the induction system.